Kingdom Levels used to be what determined your team bonus when you were being invaded, and also when invading, in kingdoms you had leveled.

Now with the bonuses being global per se, it feels like there is no point in home kingdoms. I used to enjoy finding an opponent that had a home kingdom that I knew I had maxxed so that I knew I had an edge when fighting there. I think that home kingdoms should give some other kind of little bonus (nothing major, maybe just a couple health/attacks whatever) so you can still get that thrill.

The other with kingdom leveling now, many people have their kingdoms at 10, which gives a powerful advantage when being invaded that might be tough for mid-low level people to overcome.